Andrographis paniculata Nees (Acanthaceae), commonly known as ‘Kalmegh’ is traditionally used medicinal plant. In present study callus was raised from the seeds. Maximum callus was obtained on MS medium supplemented with 2, 4- D 4.52µM/liter and IAA (5.71 µM/l). The callus and different plant parts were used for primary metabolite quantification and antioxidant activity. Maximum soluble sugars and protein found in callus, maximum amount of starch, lipid and phenolic contents were found in leaf. Leaf extract showed maximum superoxide radical scavenging activity (45.0±1.02%)) than other plant parts while root extract have maximum 2,2- diphenyl-1-picryhydrazyl (DPPH) free radical scavenging activity (71.42±1.14%)).